I haven’t tried this yet, but if you can get something like this to work please share the code.
I will probably look into this in a few weeks, when I am finished with the current milestone
Here are the positions in the code at StaticMesh.cpp : Line 290
// On cooked platforms we never need the resource data.
// TODO: Not needed in uncooked games either after PostLoad!
bool bNeedsCPUAccess = !FPlatformProperties::RequiresCookedData();
I would rather prefer to have bNeedsCPUAccess as UPROPERTY variable, so you can configure the assets according to your own needs.
Maybe we should file this as a feature request as it is a common thing you need in many scenarios.
BTW guys, I found a good answer about how to calculate the UVs when you have the barycentric coordinates. This of course doesn’t help with the issue of the UV data being cooked out, but I thought it might be useful for those that have found a workaround and are moving onto the next step: Calculate UV coordinates of 3D point on plane of mesh's triangle - Unity Answers
So i guess if i want to modify a texture to paint a splatter mark or something similar on a texture from a line trace hit, i would need c++ along with the math described in that link? None of this will be doable with current blueprint nodes?
It looks like as of 4.13, a Find Collision UV node was added.
Ref: Unreal 4.13 Notes, CTRL-F “NEW: TEXTURE COORDINATES FROM LINE TRACES”
You can use a Line Trace hit result to find the UV that was hit. But make sure to do the following:
Under Project Settings > Engine > Physics > Optimization, enable “Support UV From Hit Results”. This enables the feature but uses more CPU to store the UV information.
When performing the Line Trace, ensure, “Trace Complex” is checked.
